Cython vs Transcrypt

Cython is a free compiler for Python and the extended Cython language, used to create C extensions for Python. It translates source code into C or C++ that can be built as Python extension modules. Optional static type declarations can help produce more efficient C, while declared C and C++ types let Python code call existing C or C++ code. Cython supports source-level debugging across Python, Cython and C, and the project describes uses including wrapping external libraries, embedding CPython in applications and speeding up Python code with C modules. It can work with multidimensional NumPy arrays and integrate with low-level libraries and applications. Installation is available through pip, and some scientific Python distributions bundle it. A C compiler is required, with installation guidance for Linux, macOS and Windows. The project describes compatibility with major C and C++ compilers for CPython 3.8 and later, and characterizes PyPy support as mostly usable. Limited API and free-threading CPython support in Cython 3.1 are experimental. Cython is available under the Apache 2.0 License.

Transcrypt compiles Python source code into JavaScript for browser applications. It converts a substantial subset of Python into JavaScript 6, with optional minification, and supports features including multiple inheritance, async/await, comprehensions, and modules. Developers can call JavaScript functions from Python and use browser DOM functions and JavaScript libraries. The distribution includes optional static type validation and consistency checks, plus multilevel source maps for tracing generated JavaScript back to the original Python. Transcrypt can also compile Python server code for Node.js and use Node libraries with require(). The project recommends installing it as a Python package with pip and documents testing on Windows, Linux, and OSX. Its focus is browser development and JavaScript libraries rather than desktop Python libraries. Because code is precompiled, Python exec and eval are unsupported, although JavaScript eval is supported. C and C++ libraries are not directly supported for browser use without special measures such as compiling them to asm.js. Transcrypt is free and open source under Apache 2.0.